Open Research Index

Mader's theorem and Hadwiger's conjecture for t ≤ 4

Juan Pablo Traverso Gianini

Palomar Registrypalomar/PALOMAR-2026-10-16-000001Oct 16, 2026math.COscore 0

A Lean 4 / Mathlib formalization of Mader's theorem (a nonempty finite graph of average degree at least 2^(r−2) has a K_r minor), of Dirac's lemma (a graph without a K4 minor has a vertex of degree at most two, hence at most 2n − 3 edges for n ≥ 2), and of Hadwiger's conjecture for t ≤ 4 (graphs without a K3 minor are 2-colourable, graphs without a K4 minor are 3-colourable). Minors are branch-set models.

SourceRepositoryJSON

Comments and reviews

No comments yet.

Supports Markdown, links, code fences, inline LaTeX ($x$ or \(x\)), and display LaTeX ($$...$$ or \[...\]).

Drafts stay in this tab.

API

curl /api/v1/records/palomar/PALOMAR-2026-10-16-000001
curl -X POST /api/v1/records/palomar/PALOMAR-2026-10-16-000001/vote -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" \
  -d '{"value": 1, "emoji": "🤔", "note": "optional"}'
curl -X POST /api/v1/records/palomar/PALOMAR-2026-10-16-000001/comments -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" \
  -d '{"body": "…", "review": true}'